Contact with a surface by means of a probe or tool generates considerable information about its texture. It is as though the tool becomes an extension of the hand, and we perceive the surface as if the hand were in direct contact with it (Katz, 1925/ Krueger, 1989). Despite the fact that this type of interaction with the environment underlies such diverse activities as the use of canes by the blind, the manipulation of surgical instruments, and receiving feedback from prosthetic hands, relatively little is known about the perception of texture information via a probe and about its neural basis. In the proposed research, we will examine the perceptual information available by direct contact with textured surfaces (that is, with the bare finger) and contrast it to that available through contact with a probe. The approach will consist in pairing human psychophysical studies with neural recordings from non-human primates. There are two stages in this program of research, 1) in a set of psychophysical experiments, we will use real textures as stimuli to examine the dimensions of human texture perception, 2) we will create simulated textures from the vibratory signals generated in probes as they are scanned across the textured surface and will relate the responses of peripheral and cortical neurons to the probe-mediated textural percepts evoked by these texture-elicited vibrations. The use of identical stimuli in many of the psychophysical, peripheral, and cortical studies will allow us to directly correlate the data obtained from these studies. Both psychophysical results and neurophysiological data obtained from the use of non-human primates might prove valuable for clinical diagnosis when the normal control data are needed to compare with those from the patients who have peripheral or central nerve injuries. The results of the proposed studies have important implications for designing haptic interfaces such as remote tools used in laparoscopic surgery and tele-surgery. [unreadable] [unreadable] [unreadable]